<title>Microprecision interferometer: evaluation of new disturbance isolation solutions</title>

Abstract

This paper describes a benchmark to assess performance of six- axis vibration isolation systems. The targeted application, spaceborne interferometers, require isolation of the reaction wheel disturbances in order to stabilize the precision optical elements to the required levels. The problem is to isolate this vibrating payload from the quiet structure (spacecraft). The unique feature of this procedure is that isolator performance is measured in terms of the stability of the interferometer optical elements. Central to the procedure is the Micro-Precision Interferometer (MPI) testbed which is a hardware model of a future spaceborne optical interferometer. The isolation system under evaluation is mounted on the testbed and disturbance transfer functions are then measured from the isolator payload to the optical sensor output that must be stabilized. Off-line, the procedure combines these measured testbed transfer functions with an empirical model of the reaction wheel disturbance, in order predict isolator performance over the entire range of wheel speeds. The paper applies the procedure to four different disturbance interface conditions: hard mounted, passive hexapod isolator, active hexapod isolator and a passive elastomeric isolator. The paper contains all the necessary information to allow industry, academia or other organizations to evaluate custom designs in this testbed facility.